SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2570f68a03401835b2d23c9fb186061acd6ceb5a1dab7b3b389a7d131420b921' 
  AND token = 'osP2muLs92gu3QqvrfmpZY7Y3G4gAz2jIivvhRZxC9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}